hide setImageFilter(ptr)

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4184

Change-Id: Iad792cfdf54087ad4c424fd268559c162a9a5f5c
Reviewed-on: https://skia-review.googlesource.com/4184
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/samplecode/SampleFilterFuzz.cpp b/samplecode/SampleFilterFuzz.cpp
index 139166f..5f65c9f 100644
--- a/samplecode/SampleFilterFuzz.cpp
+++ b/samplecode/SampleFilterFuzz.cpp
@@ -736,7 +736,7 @@
     return (filter || canBeNull) ? filter : make_image_filter(canBeNull);
 }
 
-static SkImageFilter* make_serialized_image_filter() {
+static sk_sp<SkImageFilter> make_serialized_image_filter() {
     sk_sp<SkImageFilter> filter(make_image_filter(false));
     sk_sp<SkData> data(SkValidatingSerializeFlattenable(filter.get()));
     const unsigned char* ptr = static_cast<const unsigned char*>(data->data());
@@ -763,9 +763,7 @@
         }
     }
 #endif // SK_ADD_RANDOM_BIT_FLIPS
-    SkFlattenable* flattenable = SkValidatingDeserializeFlattenable(ptr, len,
-                                    SkImageFilter::GetFlattenableType());
-    return static_cast<SkImageFilter*>(flattenable);
+    return SkValidatingDeserializeImageFilter(ptr, len);
 }
 
 static void drawClippedBitmap(SkCanvas* canvas, int x, int y, const SkPaint& paint) {
@@ -777,7 +775,7 @@
 }
 
 static void do_fuzz(SkCanvas* canvas) {
-    SkImageFilter* filter = make_serialized_image_filter();
+    sk_sp<SkImageFilter> filter = make_serialized_image_filter();
 
 #ifdef SK_FUZZER_IS_VERBOSE
     static uint32_t numFilters = 0;
@@ -794,7 +792,7 @@
 #endif
 
     SkPaint paint;
-    SkSafeUnref(paint.setImageFilter(filter));
+    paint.setImageFilter(filter);
     drawClippedBitmap(canvas, 0, 0, paint);
 }